Simplify the expression. $(-7p^{4}+7p)(-2p^{4}+3p^{2})$
Explanation: First use the distributive property. $ - 7 p^4 (-2 p^4) - 7 p^4 (3 p^2) + 7 p (-2 p^4) + 7 p (3 p^2) $ Simplify. $14p^{8}-21p^{6}-14p^{5}+21p^{3}$